The rates of cannabis dependence among individuals with social anxiety are at least twice that of any other anxiety condition. Given the significant impairment associated with social anxiety and cannabis use disorders, it follows that the co-occurrence of these, two conditions can result in significant public health consequences. The paucity of research in this area is therefore surprising. The proposed series of studies aims to increase knowledge regarding this co-occurrence by: 1. Examining the temporal relationship between social anxiety and cannabis use disorders. 2. Conducting an experimental laboratory study using a social anxiety manipulation paradigm to investigate craving among individuals with social anxiety disorder and non-clinical controls. 3. Examining cannabis craving among individuals with social anxiety disorder and non-clinical controls in naturalistic settings. 4. Investigating the role of high-risk motives, expectancies, and use situations in the relationship between social anxiety and problematic cannabis use. [unreadable] [unreadable] [unreadable]